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Dog Population (dog + population)

Distribution by Scientific Domains

Life Sciences	53%
Medical Sciences	46%

Selected Abstracts

Methods and mortality results of a health survey of purebred dogs in the UK

JOURNAL OF SMALL ANIMAL PRACTICE, Issue 10 2010
V. J. Adams
Objectives: To collect information on the cause of death and longevity of dogs owned by members of the numerically largest breed clubs of 169 UK Kennel Club-recognised breeds. Methods: A cross-sectional study was carried out. Approximately 58,363 questionnaires were sent out to breed club members in 2004 (nine clubs failed to report the exact number of questionnaires sent out). Owners reported age at death and cause(s) of death for all dogs that had died within the previous 10 years. Results: A total of 13,741 questionnaires (24% response rate) containing information on 15,881 deaths were included in the analysis. Breed-specific response rates ranged from 64·7 to 4·5%. The median age at death was 11 years and 3 months (minimum=2 months, maximum=23 years and 5 months) and it varied by breed. The most common causes of death were cancer (n=4282, 27%), "old age" (n=2830, 18%) and cardiac conditions (n=1770, 11%). Clinical Significance: This survey shows breed differences in lifespan and causes of death, and the results support previous evidence that smaller breeds tend to have longer lifespan compared with larger breeds. Although many of the breeds in the study may not be representative of the general pedigree dog population in the UK, the results do contribute to the limited information currently available. [source]

Canine diabetes mellitus: from phenotype to genotype

JOURNAL OF SMALL ANIMAL PRACTICE, Issue 1 2008
B. Catchpole
Breed differences in susceptibility to diabetes mellitus in dogs suggest an underlying genetic component to the pathogenesis of the disease. There is little evidence for an equivalent of human type 2 diabetes in dogs, and it has been proposed that canine diabetes is more comparable to the type 1 form of the disease. Certain immune response genes, particularly those encoding major histocompatibility complex molecules involved in antigen presentation, are important in determining susceptibility to human type 1 diabetes. We tested the hypothesis that canine major histocompatibility complex genes (known as the dog leucocyte antigen) are associated with diabetes in dogs. A total of 530 diabetic dogs and more than 1000 controls were typed for dog leucocyte antigen, and associations were found with three specific haplotypes. The DLA-DRB1*009/DQA1*001/DQB1*008 haplotype shows the strongest association with diabetes in the UK dog population. This haplotype is common in diabetes-prone breeds (Samoyed, cairn terrier and Tibetan terrier) but rare in diabetes-resistant breeds (boxer, German shepherd dog and golden retriever), which could explain differences in the prevalence of diabetes in these different breeds. There is evidence that the DLA-DQA1*001 allele is also associated with hypothyroidism, suggesting that this could represent a common susceptibility allele for canine immune-mediated endocrinopathies. [source]

Prevalence and breed distribution of chronic pancreatitis at post-mortem examination in first-opinion dogs

JOURNAL OF SMALL ANIMAL PRACTICE, Issue 11 2007
P. J. Watson
Objectives: To assess the prevalence of canine chronic pancreatitis in first-opinion practice and identify breed associations or other risk factors. Methods: Three sections of pancreas were taken from 200 unselected canine post-mortem examinations from first-opinion practices. Sections were graded for inflammation, fibrosis and other lesions. Prevalence and relative risks of chronic pancreatitis and other pancreatic diseases were calculated. Results: The prevalence of chronic pancreatitis was 34 per cent omitting the autolysed cases. Cavalier King Charles spaniels, collies and boxers had increased relative risks of chronic pancreatitis; cocker spaniels had an increased relative risks of acute and chronic pancreatitis combined. Fifty-seven per cent of cases of chronic pancreatitis were classified histologically as moderate or marked. Forty-one per cent of cases involved all three sections. Dogs with chronic pancreatitis were more commonly female and overweight, but neither factor increased the relative risk of chronic pancreatitis. There were breed differences in histological appearances and 24·5 per cent of cases were too autolysed to interpret with an increased relative risk of autolysis in a number of large breeds. Clinical Significance: Chronic pancreatitis is a common, under-estimated disease in the first-opinion dog population with distinctive breed risks and histological appearances. [source]

Seasonal dynamics of the brown dog tick, Rhipicephalus sanguineus, on a confined dog population in Italy

MEDICAL AND VETERINARY ENTOMOLOGY, Issue 3 2010
V. LORUSSO
This study evaluated the seasonal dynamics of Rhipicephalus sanguineus (Latreille) (Acari: Ixodidae) on naturally infested dogs in a private shelter in southern Italy. From March to May 2008, 39 autochthonous mixed-breed young dogs and 10 beagles were enrolled in the study. From March 2008 until March 2009, every 21 ± 2 days, 11 body sites of each dog were checked for ticks. At each follow-up, the number of ticks, their developmental stage, sex and location on the dog's body were recorded. Adult ticks were found throughout the year, but immatures were absent in January and February. The adult tick population increased from July to August, whereas the load of immatures increased in early July and peaked in September, which suggests that R. sanguineus develops one generation per year in this area. The mean number of immature ticks per infested dog was higher than that of adults from March to October 2008. Ears, interdigital areas and armpits were the most frequent attachment sites of adult ticks. At the last follow-up, a total of 2266 ticks were collected and identified as R. sanguineus. The results suggest that R. sanguineus develops one generation per year in the study area, but that it infests dogs in all seasons. This information should be taken into account when planning control programmes against this tick species and the pathogens it transmits. [source]

Ethics and Genetic Selection in Purebred Dogs

REPRODUCTION IN DOMESTIC ANIMALS, Issue 1 2003
VN Meyers-Wallen
Contents There is an ongoing revolution in medicine that is changing the way that veterinarians will be counselling clients regarding inherited disorders. Clinical applications will emerge rapidly in veterinary medicine as we obtain new information from canine and comparative genome projects (Meyers-Wallen 2001: Relevance of the canine genome project to veterinary medical practice. International Veterinary Information Service, New York). The canine genome project is described by three events: mapping markers on canine chromosomes, mapping gene locations on canine chromosomes (Breen et al. 2001: Genome Res. 11, 1784,1795), and obtaining the nucleotide sequence of the entire canine genome. Information from such research has provided a few DNA tests for single gene mutations [Aguirre 2000: DNA testing for inherited canine diseases. In: Bonagura, J (ed), Current Veterinary Therapy XIII. Philadelphia WB Saunders Co, 909,913]. Eventually it will lead to testing of thousands of genes at a time and production of DNA profiles on individual animals. The DNA profile of each dog could be screened for all known genetic disease and will be useful in counselling breeders. As part of the pre-breeding examination, DNA profiles of prospective parents could be compared, and the probability of offspring being affected with genetic disorders or inheriting desirable traits could be calculated. Once we can examine thousands of genes of individuals easily, we have powerful tools to reduce the frequency of, or eliminate, deleterious genes from a population. When we understand polygenic inheritance, we can potentially eliminate whole groups of deleterious genes from populations. The effect of such selection on a widespread basis within a breed could rapidly improve health within a few generations. However, until we have enough information on gene interaction, we will not know whether some of these genes have other functions that we wish to retain. And, other population effects should not be ignored. At least initially it may be best to use this new genetic information to avoid mating combinations that we know will produce affected animals, rather than to eliminate whole groups of genes from a population. This is particularly important for breeds with small gene pools, where it is difficult to maintain genetic diversity. Finally, we will eventually have enough information about canine gene function to select for specific genes encoding desirable traits and increase their frequencies in a population. This is similar to breeding practices that have been applied to animals for hundreds of years. The difference is that we will have a large pool of objective data that we can use rapidly on many individuals at a time. This has great potential to improve the health of the dog population as a whole. However, if we or our breeder clients make an error, we can inadvertently cause harm through massive, rapid selection. Therefore, we should probably not be advising clients on polygenic traits or recommend large scale changes in gene frequencies in populations until much more knowledge of gene interaction is obtained. By then it is likely that computer modelling will be available to predict the effect of changing one or several gene frequencies in a dog population over time. And as new mutations are likely to arise in the future, these tools will be needed indefinitely to detect, treat and eliminate genetic disorders from dog populations. Information available from genetic research will only be useful in improving canine health if veterinarians have the knowledge and skills to use it ethically and responsibly. There is not only a great potential to improve overall canine health through genetic selection, but also the potential to do harm if we fail to maintain genetic diversity. Our profession must be in a position to correctly advise clients on the application of this information to individual dogs as well as to populations of dogs, and particularly purebred dogs. [source]

Domestic dogs as an edge effect in the Brasília National Park, Brazil: interactions with native mammals

ANIMAL CONSERVATION, Issue 5 2009
A. C. R. Lacerda
Abstract Edge effects are a well-known result of habitat fragmentation. However, little has been published on fragmentation, isolation and the intrusive influence from the surrounding matrix at the landscape level. The objectives of the present study are to evaluate the presence of dogs in the Brasília National Park (BNP) in relation to habitat type and the influence from the surrounding matrix. In addition, this study examines the response of the native mammal fauna to the presence of dogs. Track stations were built along dirt roads in the BNP and subsequently examined for the presence or absence of tracks. We used a stepwise logistic regression to model the occurrence of five mammal species relative to habitat variables, with an ,=0.05 to determine whether to enter and retain a variable in the model. A simulation of each species occurrence probability was conducted using a combination of selected habitat variables in a resource selection probability function. Results indicate a negative relationship between distance from the BNP edge and the probability of dog occurrences. From an ecological perspective, the presence of dogs inside the BNP indicates an edge effect. The occurrence of the maned wolf was positively associated with distance from a garbage dump site and negatively associated with the presence of dog tracks. The maned wolf and giant anteater seem to avoid areas near the garbage dump as well as areas with dog tracks. There is no support for the possible existence of a feral dog population inside the BNP, but the effects of free-ranging dogs on the wildlife population in such an isolated protected area must not be neglected. Domestic dog Canis familiaris populations and disease control programs should be established in the urban, sub-urban and rural areas surrounding the BNP, along with the complete removal of the garbage dump from the BNP surroundings. [source]

Soft tissue sarcomas and mast cell tumours in dogs; clinical behaviour and response to surgery

AUSTRALIAN VETERINARY JOURNAL, Issue 12 2003
M BAKER-GABBy
Objective To characterise the types of canine soft tissue sarcoma and mast cell tumour treated surgically at the University Veterinary Centre, Sydney. To evaluate the success of surgical treatment of these tumours and identify variables predictive of local recurrence and survival. To establish whether conclusions drawn from previous international studies are applicable to the University Veterinary Centre, Sydney, dog population and vice versa. Design Clinical presentation and results of surgical excision of 54 soft tissue sarcomas and 70 mast cell tumours affecting the trunk and limbs of dogs at the University Veterinary Centre, Sydney, between 1989 and 2001 were reviewed retrospectively. Results Cross-bred dogs and Rhodesian Ridgebacks were at significantly greater risk of developing soft tissue sarcomas, and Boxers, Australian Cattle Dogs and Staffordshire Bull Terriers were at significantly greater risk of developing mast cell tumours than other breeds. Fine needle aspiration biopsy yielded a correct diagnosis in 62.5% of soft tissue sarcomas and 96% of mast cell tumours. Local recurrence was encountered after surgical excision in 7.4% of soft tissue sarcomas and 7.3% of mast cell tumours. Metastasis occurred in 6% of soft tissue sarcomas and 12% of mast cell tumours. The most significant risk factors for local recurrence were contaminated surgical margins (soft tissue sarcomas) and histological grade (mast cell tumours). Due to the low number of animals experiencing metastasis, no conclusions could be drawn about significant risk factors. Conclusions Aggressive surgical management of soft tissue sarcomas and mast cell tumours is associated with a low incidence of local recurrence. The type, location and behaviour of mast cell tumours and soft tissue sarcomas in the population of dogs presented to the University Veterinary Centre, Sydney are similar to those reported by others. [source]

Dogs Canis familiaris as carnivores: their role and function in intraguild competition

MAMMAL REVIEW, Issue 4 2009
ABI TAMIM VANAK
ABSTRACT 1Dogs Canis familiaris are the world's most common carnivore and are known to interact with wildlife as predators, prey, competitors, and disease reservoirs or vectors. 2Despite these varied roles in the community, the interaction of dogs with sympatric wild carnivore species is poorly understood. We review how dogs have been classified in the literature, and illustrate how the location and ranging behaviour of dogs are important factors in predicting their interactions with wild prey and carnivores. 3We detail evidence of dogs as intraguild competitors with sympatric carnivores in the context of exploitative, interference and apparent competition. 4Dogs can have localized impacts on prey populations, but in general they are not exploitative competitors with carnivores. Rather, most dog populations are highly dependent on human-derived food and gain a relatively small proportion of their diet from wild prey. However, because of human-derived food subsidies, dogs can occur at high population densities and thus could potentially outcompete native carnivores, especially when prey is limited. 5Dogs can be effective interference competitors, especially with medium-sized and small carnivores. Dogs may fill the role of an interactive medium-sized canid within the carnivore community, especially in areas where the native large carnivore community is depauperate. 6Dogs can also be reservoirs of pathogens, because most populations around the world are free-ranging and unvaccinated. Diseases such as rabies and canine distemper have resulted in severe population declines in several endangered carnivores coexisting with high-density dog populations. Dogs can therefore be viewed as pathogen-mediated apparent competitors, capable of facilitating large-scale population declines in carnivores. 7Based on this information, we propose conceptual models that use dog population size and ranging patterns to predict the potential for dogs to be intraguild competitors. We discuss how interactions between dogs and carnivores might influence native carnivore communities. [source]

Patterns of population subdivision, gene flow and genetic variability in the African wild dog (Lycaon pictus)

MOLECULAR ECOLOGY, Issue 7 2001
D. J. Girman
Abstract African wild dogs are large, highly mobile carnivores that are known to disperse over considerable distances and are rare throughout much of their geographical range. Consequently, genetic variation within and differentiation between geographically separated populations is predicted to be minimal. We determined the genetic diversity of mitochondrial DNA (mtDNA) control region sequences and microsatellite loci in seven populations of African wild dogs. Analysis of mtDNA nucleotide diversity suggests that, historically, wild dog populations have been small relative to other large carnivores. However, population declines due to recent habitat loss have not caused a dramatic reduction in genetic diversity. We found one historical and eight recent mtDNA genotypes in 280 individuals that defined two highly divergent clades. In contrast to a previous, more limited, mtDNA analysis, sequences from these clades are not geographically restricted to eastern or southern African populations. Rather, we found a large admixture zone spanning populations from Botswana, Zimbabwe and south-eastern Tanzania. Mitochondrial and microsatellite differentiation between populations was significant and unique mtDNA genotypes and alleles characterized the populations. However, gene flow estimates (Nm) based on microsatellite data were generally greater than one migrant per generation. In contrast, gene flow estimates based on the mtDNA control region were lower than expected given differences in the mode of inheritance of mitochondrial and nuclear markers which suggests a male bias in long-distance dispersal. [source]

Ethics and Genetic Selection in Purebred Dogs

Investigating the distribution of prairie dogs in an urban landscape

ANIMAL CONSERVATION, Issue 3 2009
S. B. Magle
Abstract Habitat fragmentation is a prevalent threat to biological diversity, and urbanization is a primary agent of fragmentation and a leading cause of species endangerment. Landscape biogeographic and local habitat characteristics can be important determinants of the distribution of species in habitat patches in urban landscapes. However, the specifics of which characteristics are most critical to maintaining biological diversity are not fully known for prairie ecosystems, especially in fragmented urban habitat. This study focuses on black-tailed prairie dogs along an urban gradient in Denver, CO. Prairie dogs have declined precipitously throughout the region and are an essential part of the prairie ecosystem, making them excellent study subjects. We identified a series of habitat fragments along a gradient of urbanization in the fully urbanized areas and south suburbs of Denver, CO, both containing and not containing prairie dogs. Local characteristics, including fragment slope and vegetative cover, and landscape characteristics, including fragment size, age and connectivity, were measured on each fragment. We used likelihood-based methods to explore which variables most accurately predicted prairie dog occurrence within our study area. Multiple factors influenced the distribution of prairie dogs in urban settings, with colony connectivity the strongest predictor of occupancy. Large and recently isolated fragments near other prairie dog colonies, flat areas and those with high graminoid cover were most likely to support prairie dog populations. Our study provides the first attempt to model prairie dog occurrence in highly fragmented urban habitat and has important implications for the management and conservation of prairie dogs. [source]

Molecular structure in peripheral dog breeds: Portuguese native breeds as a case study

ANIMAL GENETICS, Issue 4 2009
A. E. Pires
Summary Genetic variability in purebred dogs is known to be highly structured, with differences among breeds accounting for ,30% of the genetic variation. However, analysis of the genetic structure in non-cosmopolitan breeds and local populations is still limited. Nine Portuguese native dog breeds, and other peripheral dog populations (five) with regional affinities, were characterized using 16 microsatellites and 225 amplified fragment length polymorphism (AFLP) markers, and the pattern of genetic differentiation was investigated. Although the level of breed differentiation detected is below that of other dog breeds, there is in most cases a correlation between breed affiliation and molecular structure. AFLP markers and Bayesian clustering methods allowed an average of 73.1% of individuals to be correctly assigned to source populations, providing robust genotypic assessment of breed affiliation. A geographical genetic structure was also detected, which suggests a limited influence of African dogs on the Iberian breeds. The sampling effect on the estimation of population structure was evaluated and there was a 2.2% decrease in genetic differentiation among breeds when working animals were included. Genetic diversity of stray dogs was also assessed and there is no evidence that they pose a threat to the preservation of the gene pool of native dog breeds. [source]